Combustion is more complete with ron 97 compare 95 and generate more power (KW) bcoz ron 97 gross heating value is higher than ron 95 ....shell/petronas/exxxon/BHP used the same based fuel of ron 95 or 97 from our refineries in Melaka,PD or Terengganu........the only different is the plug in additives.......... I’m working as org minyak fo so many years and guess what? Im using SHELL ron 95 off all my contibnental car (Merz/BM)........ to me it is ok as long as our car maintenance are well taken care coz ron 95 generate a bit more carbon during combustion take place compare 97....actuall gross heating value 95 is not much different with 97....for diesel car..guys you have to be extra careful about maintenance...don’t take it lightly.....coz our diesel spec is not the same from euro spec.........that is the realty.......I was involve during design, and construction stage to one of our refineries.....